There are nearly 2,800 working satellites in space. That’s according to the Union of Concerned Scientists. We depend on these devices for technology we use every day, such as video calls and weather tracking. Scientists use them to study the Earth and space.

But many other satellites in orbit are broken and still floating around up there. Some of these eventually fall back toward the Earth. They either land or burn up in the atmosphere. Space junk is a problem. Debris floating around the Earth puts technology and future space missions at risk. Experts are working on a solution.

SUPER SIZE Space junk comes in different sizes. This big chunk from a rocket fell to Earth in May. 

Orbital debris is a type of space junk. It’s any human-made object that has stopped working but continues to float around the Earth. This includes abandoned satellites and pieces of spacecraft. “It’s a legacy problem,” Vitali Braun told TIME for Kids. He’s an engineer at the European Space Agency (ESA). “You have a satellite or rocket stages put into space in the 1960s, and they’re still there.”

Space junk can also include fragments of objects. These occur when satellites collide with things. Or they result from an object crashing into an old rocket stage that has fuel in it. This can cause an explosion.

DAMAGED This solar panel from the Hubble Space Telescope was damaged by orbital debris.

Heather Cowardin works at NASA. She says the United States is tracking more than 23,000 pieces of space debris (see “Too Much Junk”). These tiny fragments damage working satellites. This can affect research in space.

SPACE SWEEPER Astroscale and Japanese government officials pose in front of an ELSA-d satellite. It will use magnets to collect space debris.

Companies are working to clean up the debris. Astroscale is one based in Japan. It plans to launch a mission called ELSA-d. The mission will try using magnets to collect space debris. The idea is to get companies to put magnetic plates on the satellites they launch. An Astroscale spacecraft could attach to the magnetic plate and remove the satellite when it failed.

TRASH COLLECTORS from Astroscale show the tools they hope to use to remove space junk

Another mission is led by a Swiss company called ClearSpace. ClearSpace plans to launch a debris-removal spacecraft in 2025. The craft will grab a piece of an old rocket, slow it down, and eject it back to Earth.

TRASH COLLECTORS from ClearSpace show the tool they hope to use to remove space junk.

Governments are trying to help too. Some are updating their space guidelines. This is to limit the amount of debris created. The sustainability of space “is not a single-agency or a single-country problem that we can solve,” says Cowardin. “We have to work on this together.”